LOCATION MONCISCO NMEstablished Series
TAXONOMIC CLASS: Loamy-skeletal over fragmental, mixed, active, mesic Typic Haplocalcids
TYPICAL PEDON: Moncisco extremely channery sandy clay loam -- on a convex backslope of a hill sloping 22 percent to the south at 5,760 feet elevation -- rangeland. (Colors are for dry soil unless otherwise noted. When described, the soil was dry throughout.)
A-- 0 to 2 inches; pale brown (10YR 6/3) extremely channery sandy clay loam, brown (10YR 4/3) moist; moderate medium platy structure parting to weak fine granular; soft, very friable, slightly sticky and slightly plastic; few fine and very fine roots; common very fine vesicular pores; 70 percent channers and 5 percent gravel; strongly effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (1 to 5 inches thick)
Bk-- 2 to 11 inches; light reddish brown (5YR 6/3) extremely channery sandy clay loam, reddish brown (5YR 4/4) moist; weak thick platy structure parting to moderate very fine granular; soft, very friable, slightly sticky and slightly plastic; common fine and very fine roots; few very fine irregular pores; 70 percent channers, 5 percent gravel and 5 percent flagstones; violently effervescent, secondary calcium carbonates segregated as many fine and medium irregular shaped accumulations on rock fragments; moderately alkaline (pH 8.2); abrupt wavy boundary. (7 to 16 inches thick)
2Cky-- 11 to 16 inches; light red (2.5YR 6/6) hard porcelanite fragments, red (2.5YR 4/8) moist; highly fractured platy and angular rock structure; loose; few fine and common very fine roots in cracks; common vertical and horizontal interstices less than 1 mm wide are filled with powdery calcium carbonates and gypsum crystals, few vertical interstices 1 to 3 mm wide lack fine earth; 80 percent channers and 10 percent flagstones; secondary gypsum crystals segregated as very few fine irregularly shaped accumulations on rock fragments; strongly effervescent, secondary calcium carbonates segregated as few fine irregularly shaped accumulations on rock fragments; gradual smooth boundary. (0 to 14 inches thick)
2Cy-- 16 to 70 inches; red (10R 5/8) hard porcelanite fragments, red (10R 4/8) moist; highly fractured platy and angular rock structure; loose; few fine and very fine roots in cracks; vertical and horizontal interstices lack fine earth; 75 percent channers and 20 percent flagstones; secondary gypsum crystals segregated as very few fine and medium irregularly shaped accumulations on rock fragments.
TYPE LOCATION: San Juan County, New Mexico; on the Navajo Indian Reservation about 25 miles east-northeast of Sheep Springs; 3,400 feet south and 350 feet east of the northwest corner of sec. 1, T. 23 N., R. 14 W.; Latitude 36 degrees 15 minutes 13 seconds North, and Longitude 108 degrees 17 minutes 17 seconds West.
RANGE IN CHARACTERISTICS:
Soil moisture - Typically, the soil moisture control section (SMCS) is intermittently moist in some part from July to October and December to mid-April. Driest during May and June. Typic aridic soil moisture regime.
Soil temperature - 52 to 57 degrees F.
Soil depth - greater than 60 inches to bedrock
Depth to calcic horizon - 1 to 5 inches
Depth to fragmental material - 11 to 20 inches
Reaction - slightly alkaline or moderately alkaline
A horizon
Value: 5 or 6 dry
Chroma: 3 or 4, dry or moist
Organic carbon content: 0.1 to 0.3 percent
Calcium carbonate equivalence: 1 to 3 percent
Salinity: less than 2 dS/m
Rock fragments: 60 to 75 percent;
0 to 10 percent gravel,
60 to 70 percent channers less than 3 inches long,
0 to 5 percent flagstones less than 10 inches long
Bk horizon
Hue: 5YR, 7.5YR
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 2 through 4, dry or moist
Organic carbon content: 0.1 to 0.3 percent
Clay content: 12 to 25 percent
Calcium carbonate equivalence: 5 to 20 percent. (In those profiles with sandy clay loam textures the carbonates exceed 15 percent and in those with sandy loam textures the carbonate percentage may range as low as 5 percent)
Salinity, mmhos/cm: 4 to 8 dS/m
Texture: extremely channery sandy clay loam, extremely channery sandy loam
Rock fragments: 70 to 85 percent;
0 to 5 percent gravel,
65 to 75 percent channers, 10 to 15 percent are greater than 3 inches long,
0 to 10 percent flagstones, 0 to 5 percent are greater than 10 inches long
2Cky or 2Cy horizons
Hue: 10R, 2.5YR, 5YR
Value: 4 through 7 dry, 4 through 6 moist
Chroma: 4 through 8, dry or moist
Organic carbon content: less than 0.1 percent
Calcium carbonate equivalence: 0 to 3 percent
Gypsum content: 0 to 2 percent
Salinity: less than 2 dS/m
Texture: fragmental
Rock fragments: 90 to 100 percent;
0 to 10 percent gravel,
60 to 85 percent channers, 10 to 15 percent are greater than 3 inches long,
5 to 20 percent angular cobbles or flagstones, 0 to 5 percent are greater than 10 inches long,
0 to 5 percent stones
Other features: some pedons have horizons of channery loamy sand or extremely channery sandy loam below 40 inches
COMPETING SERIES: There are no competitors.
GEOGRAPHIC SETTING: Moncisco soils are on footslopes and backslopes of hills underlain by beds of fractured porcelanite. The porcelanite occurs as baked and fused shale and sandstone associated with burned coal seams of the Cretaceous Fruitland and Menefee Formations. Moncisco soils formed in eolian material derived from Cretaceous sandstone and residuum derived from fractured porcelanite. Slopes range from 2 to 45 percent. Elevation ranges from 5,600 to 6,300 feet. The mean annual precipitation is 5 to 10 inches with 35 to 60 percent falling as rain from high-intensity thunderstorms between July and September. The mean annual temperature is 50 to 55 degrees F. The average frost-free period is 130 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chipeta, Huerfano, and Razito soils. Chipeta soils lack diagnostic horizons and are shallow to shale on footslopes below Moncisco soils. Huerfano soils have natric horizons and are shallow to shale on toeslopes and knolls of undulating plateaus. Razito soils are very deep and occur in stable linear dunes of undulating plateaus.
DRAINAGE AND PERMEABILITY: Excessively drained; rapid runoff; moderate permeability in the upper profile and very rapid permeability below.
USE AND VEGETATION: Moncisco soils are used for livestock grazing and as a source of road gravel. Present vegetation is galleta, alkali sacaton, Indian ricegrass, bottlebrush squirreltail, shadscale, and winterfat.
DISTRIBUTION AND EXTENT: Moncisco soils are of small extent on the western San Juan Basin portion of the Colorado Plateau province in northwest New Mexico. MLRA 35, LRR-D
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Shiprock Area, Parts of San Juan County, New Mexico and Apache County, Arizona; 1993.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 2 inches. (A horizon)
Calcic horizon - The zone from 2 to 11 inches. (Bk horizon)
Contrasting particle-size class - The presence of fragmental material between 10 and 40 inches. (2Cky and 2Cy horizons)
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Tenth Edition, 2006
ADDITIONAL DATA: Organic carbon and gypsum values are estimated. Salinity values were determined on four pedons, including the type location, with an Instant EC Salinity kit. Calcium carbonate equivalence determined with a field volume calcimeter.
Updated and revised for the correlation of Ft. Defiance Area AZ715 2/08 DWD